86 folsom [88] 



NEANURA GIGANTEA Tull. 



(PI. iv, fig. I ; PI. vi, figs. 11-13.) 



Anura gigantea Tullberg, Ofv. k. vet. Akad. forh., xxxiii, no. 5, p. 41, taf. 



11, fig. 59, 1876 (Siberia). — Schott, K. sven. vet. Akad. hand., xxv, 



no. 11, p. 94, 1894 (Siberia). 

 Neanura gigantea Schakfer, Fauna Arctica, I, lief. 2, p. 240, 1900. 



General color of alcoholic specimens indigo blue, with conspicuous 

 blackish tubercles (fig. 1); living examples pruinose (Tullberg). 

 Head twice as broad as long, with twelve large tubercles, including 

 those bearing the eyes, arranged as in fig. 1. Eyes (fig. 11) five on 

 either side. Postantennal organs (figs. 1 1, 12) each composed of more 

 than 100 clavate papilla? forming a rosette. Antennas half as long as 

 the head, conical, with segments related in length as 4 : 3 : 2 : 6 ; basal 

 and second segments half as long as broad ; third and fourth coales- 

 cent ; the minute antennal tubercles become successively smaller on 

 each segment. Body oval in dorsal aspect ; the number of large tuber- 

 cles on each successive segment is, respectively, 6, 8, 8, 8, S, S, 8, 6, 2 ; 

 the tubercle at either end of each transverse row is behind the others, 

 on the first seven segments ; on the seventh, both are also ventral and 

 inconspicuous ; on the eighth, four are ventral and two dorsal ; the 

 ninth segment is bent under and bears two small tubercles. Legs 

 short and stout; claws (fig. 13) alike, stout, uniformly curving and 

 tapering, strongly unidentate on the inner margin and minutely tuber- 

 culate. Cuticula finely tuberculate ; large tubercles also reticulate 

 (fig. 11), bearing several long stiff yellow setaa. Maximum length, 

 5 mm. 



Two forms occur : broad ones, in which breadth is to length as 

 1 : 1.79 ; and narrow ones, in which the ratio is 1 : 2.27. This differ- 

 ence of proportion is independent of age, as it exists between speci- 

 mens of equal length ; it is found in other species of Neanura, and 

 is presumably a sexual distinction. 



Twenty-five specimens, St. Paul Island, Bering Sea, 1897. 



The original description, although brief, suffices to place this well 

 marked and monstrous species. Tullberg and Schott have recorded it 

 from several localities in Siberia, Yenisei River (Latitude 61 ° to 73°). 

 Schott also notes the species from the vicinity of St. Lawrence Bay. 

 Tullberg (1876, p. 29) is confident that Neanura gigantea does not 

 occur in Nova Zembla, Spitsbergen or Greenland. 



